The present invention is an improvement on an earlier device that has been used by educators to demonstrate how electrostatic charges are created. The earlier device is made of a transparent plastic tube. The tube is closed at each end and holds a large number of small particles. These particles are typically made from styrofoam or another low density material that can hold an electrostatic charge. Rubbing the tube with a cloth creates a positive and negative charge between the walls of the tube and the particles. The particles stick to the inside walls of the tube, since opposite charges create an attractive force.
Teachers use the device in a classroom to explain simple concepts relating to electricity, electrical charges, and the like. The problem with the device is that the particles tend to not lose their charge quickly, which makes it hard to repeat demonstrations during a classroom lecture. This also tends to reduce the effectiveness of the tool as a teaching aid.
The invention is an improvement on the device described above. The differences between the improvement and the above device are summarized and described below.